Wear tester



y 17, 1951 w. B. PETKEWICZ 2,561,133

WEAR TESTER Filed April 1, 1947 2 Sheets-Sheet l 0 s "a; (\l (I) &

INVEN TOR WILLIAM B. PETKEWICZ July 17, 1951 w. B. PETKEWICZ 2,561,133

WEAR TESTER Filed April 1, 1947 2 Sheets-Sheet 2 l INVENTQR WILLIAM B. PETKEWICZ ATTORNEYS Patented July 17, 1951 UNITED STATES PATENT WEAR TESTER Application April 1, 1947, Serial-No.738g667 M 3 Claims. 1.

The present invention relatestowear testing apparatus and is concerned primarily with. a wear tester. designed for. use on paper making feltsand comparable fabrics.

In providing. testing apparatus-of thisetype it is highl'i important that. the actual conditionsof usage be. artificially reproduced to as great an extent as. possible. This. means the testing should be carriedloutunder: conditions closely simulating those inwhich=the particular subject is used. When a paper making felt is employed tensionis not constantly: applied. thereto. It is released at intermittent intervalst Thus, it is highly desirable: in testing apparatus for. such felts-to...reproduce this condition.

Accordingly, thevinvention. has in view, as an important object; the provision of weartesting apparatus of the character indicated which includes means for placing a fabric under; intermittent tension. Inasmuch as paper making felts are also subjecttofriction, the wear testing apparatus provided must also -produc'e as comparable amount of friction;

A further object; therefore; lies' in-the provision of wear testing apparatus of the typeaforesaidiin whichthe'frictionalengagement is achieved under conditions of intermittent tension.

The main utility o'f awear testeris to compare one piece of material to another. Thus, when one piece is testedsitisimportantithat the-second piece be tested:v under identical conditions- In order to establish the frictional engagement it is necessary that theifelt or other: material be urged against the-frictional elements-under pressure. In the" devices heretofore employed it has been difiicult',. if'not impossible; to assure that: this same pressure is: exactly reproduce-d1 in" different tests.

A furth'en'obje'ot;therefore; istne provision' of wear testing apparatus "inoludingmeans-for subjetting sheet material to friction while under intermittent: tension and with anaccurately predeterminedpre'ssure on the material In achieving-ithese obiects' two knurled frietional rolls are emplcyediin' conjunctionwith a material carrying roll; All of these rolls are mounted for/rotation at the sameangular velocity; That is the'yhave the same number of-rev oluti'ons-per minute. The frictional effect is ob tained by making the several -'roll's' of difiere'nt uiameters so that their circumferential velocity varies.

The material carrying roll isso arranged 'witli respect to the knurled rolls" that the engagement ofthematerial between one of'the knurled rolls and materialcarryingrolllcauses a tension in one direction while the. corresponding engagement with the otheriknurled roll creates a. tension in a reverse. direction. This results lathe alternate tensioning andrelease. of the material A-further somewhat moredetailed object of the invention-is the provisionpfi new and improved means for urging. the material. carrying rolls against theknurled rolls. This end is attained by: suspending the materialcarryingroll andassociatingwith this suspension aweight which. is effective to force. the material. carrying r011 against theknurledlrolls under. gravity action.

Moreindetail'; afurther ob'j ectis. the provision of. apparatus of .the character. aforesaid. inwhich the pressure. on. the. material carryingroll.v may be variedas .occasion.demands. This. is achieved by making the weight, whichurges the. material carrying .roll' against theknurledrolls, adjustable.

A further. objectlies in the provision of a wear testing apparatus of the type above indicated which issusceptible of.carrying.out.testing. operations on paper making felts and similar material undeneither wet.or dry conditions. In attaining thisend a pan is positioned immediately beneath the material carrying rolland'this pan is .-.adapted to receive water' or other. solution. toiwhicha paper. making, felt isllkely tobe. subjectedduring actualservice usage. The..materia1..carrying roll extends into. the panvand las .it' is rotated,-., the material. carried thereby is wetted.

Various. other and. more. detailed objects and advantages such.v as. arise in. connection. with carrying out the. above notedideas-ina practical embodiment will in part-become apparent and in part be hereinafter statedvas. the. description. of the invention proceeds.

The invention,.therefore, comprises wear test.- ing. apparatus including means for subjecting sheet-material to an. accurately predetermined friction under conditions. of. alternating tension and'rel'ease of the material.

For a full and more complete understanding. of the invention, reference. may. be hadoto. theiollowing description and accompanying drawings wherein:

Figure '1' is a perspective view. ofiwear. testing apparatus. designectin accordance with. the precepts. or. this invention;

Figure 2 is. an. enlarged perspective view with the cover. removed-and certain parts broken away and shown in section;

Figure 3 is a longitudinal section takenabout on the planesrepresented. by. thelines 3'-3 of Figure. 1 and Figure 4 is a detailed showing of the rolls per se taken on a plane normal to the axis of the rolls. This view is taken about on the plane represented by the line 4-4 of Figure 2.

Referring now to the drawing wherein like reference characters denote corresponding parts, the wear testing apparatus provided by this invention may be mounted within a casing comprising a bottom I6, end walls I I and l2, and a rear wall I3 which is curved at its top to provide a protecting canopy I4. Upstanding from the base I6 are a pair of vertical supports I5 and I6. These supports I5 and I6 are provided with openings in which certain shafts are journaled as will be hereinafter pointed out. They also are provided with slots I7 extending upwardly from the bottom and on their outer faces carry plates I8 which are formed with slots in alignment with the slots IT.

A pair of shafts I9 are journaled in openings formed by the supports I5 and I6 are are in alignment; Between the latter elements the shafts I9 carry a knurled roll 26 which is divided into sections by the annular grooves 2 I. In the illustrated embodiment of the invention the roll is shown as divided into six sections. Obviously this can be varied and is not a limitation of the invention. At each end the shafts i9 carry a gear 22 that is drivably mounted on the shaft between the respective support and end wall.

Another pair of shafts 23 are also journaled between the supports I5 and I6 and have their ends projecting therebeyond. Between the members I5 and I6 the shafts 23 carry a knurled roll 24 which is divided into sections corresponding in number and arrangement to the sections of the knurled roll 26. The purpose of providing these sections is to accommodate the testing of different fabrics simultaneously. At each end spaced between the respective support and end wall the shafts 23 have drivably mounted thereon a gear 25.

Slidably positioned in each of the slots I1 is a shaft 26. Between the members I5 and I6 the shafts 26 drivably carry a material carrying roll 21. Upon referring to Figure 4 it will be noted that this roll 2'! is formed with a groove 23 extending lengthwise thereof. The material to be tested is shown at 29. Each piece of material is anchored in position on the roll 2'! through the medium of a block 39 which clamps the ends of the material against the walls of the groove 28 and the block 30 is held in this position by the screw shown at 3I. Each of the shafts 26 carry, adjacent to its free end, a pinion 34 which is drivably mounted thereon.

The material carrying roll 2'! extends down into a pan 32 which may be supported in position by the bolt and nut arrangement shown at v33.. When the material 29 is to be tested wet,

the pan 32 is filled with water, or other fluid to which a paper making felt is subjected during usage, whereby the material is wetted. There are times during a paper making operation when solutions having various degrees of acidity or alkalinity are employed. The felts are subject to these solutions and if service conditions are to be accurately reproduced in the testing apparatus, provision must be made for immersing the materials in such solutions. This is accommodated by the pan 32. Brackets shown at 35 are carried on the inner faces of the members I5 and I6 and cooperate with the bolts 33 in positioning the pan 32.

Extending through the aligned slots of the plate I8 and the respective support is a shaft member 4 36. Between the members I5 and I6 the shafts 36 carry a weight 31 which may take the form of the roll illustrated. Outside the respective supports I5 and I6 each of the shafts 36 carries a gear 38 and the shaft is continued therebeyond to provide a shaft section 39 that is adapted to receive removable weight members 46. The latter is held in position by the nut shown at 4!.

An endless chain 42 passes over the gears 22 and 25 and beneath the pinion 34 so as to hold the material carrying roll in a suspended position. Likewise, the chain 42 passes beneath the gears 38 and suspends the weights 3'! and 40 in such a manner that they urge the material carrying roll 21 upwardly against the knurled rolls 2!] and 24.

Each of the shafts I9, 23, and 26 are driven at the same number of revolutions per minute. Thus, the angular velocity is uniform. However, as illustrated in the drawings, the knurled roll 20 is of one diameter, the roll 24 of another, and the roll 27 of still another. Thus, each of these rolls has a different circumferential velocity, Moreover, it will be noted from Figure 4, that, due to the arrangement of the rolls, the material is tensioned in one direction by the engagement between the rolls 26 and 21 and in the opposite direction by the engagement between the rolls 24 and 21. The engagement between the rolls 26 and 21 is depicted at the point a while that between the rolls 24 and 21 is shown at 1). Between the points a and b the material 26 is released.

The several rolls may be driven in any preferred manner. As shown in the drawing, the end wall l2 may be formed with an opening 43 through which the shaft I9 is extended. Any appropriate power source may be availed of to drive the shaft I9.

Operation In using the above described apparatus specimens of the material to be tested will be anchored to the roll 21 in the manner depicted. A record will be kept of the total weightof the roll 31 and weights 40 as these determine the pressure under which the roll 21 is urged against the knurled rolls. The shaft I9 will be driven at a predetermined rate of speed and the material is tested a prescribed period of time.

If the material is to be tested dry, the pan 32 ma be removed or left dry; while if it is to be tested wet, this pan will be filled with water, or any other solution to which paper making felt might be subjected. After the tests have been completed, the specimens may be examined and it will be known just how much they will act under certain conditions, all of which may be accurately recorded. It is then possible to submit other specimens to the tests under conditions which will accurately duplicate those of the first test. Thus, the apparatus provided hereby is peculiarly adapted for the testing of materials and keeping an accurate record of the conditions under which they were tested.

While a preferred specific embodiment of the invention is hereinbefore set forth, it is to be clearly understood that the invention is not to be limited to the exact constructions illustrated and described because various modifications of these details may be provided in putting the invention into practice within the purview of the appended claims.

What is claimed is:

1. In wear testing apparatus, a friction roll having a gear at each end, a second friction roll of a diameter different from said first friction roll and having a gear at each end, a material carrying roll adapted to engage said friction rolls and having a diameter different from that of either of said friction rolls, a pinion at each end of said material carrying roll, a pair of endless chains, one being arranged at each end of said rolls so that it passes over said gears and beneath said pinion to suspend said material carrying roll, a gear engaging each of said chains Within the lower bends thereof, and an adjustable weight carried by said gears.

2. Apparatus of the character described comprising a base, supporting members upstanding from said base in spaced relation, a shaft journaled in said supports and carrying therebetween a friction roll, a second shaft journaled in said supports and carrying therebetween a second friction roll of a diameter different from said first friction roll, said supporting members being formed with slots beneath the bearings of said shafts, shaft means in said slots and carrying between said supporting members a material carrying roll, suspension means for said shaft means, means cooperating with said. suspension means for urging said material carrying roll against said friction rolls under gravity action, and a water pan carried by said supporting me1nbers beneath said material carrying roll into which said material carrying roll is adapted to 3 project.

3. Apparatus of the character described comprising a base, supporting members upstanding from said base in spaced relation, a friction roll positioned between said supports and including shaft means journaled therein, a second friction roll of a diameter different from said first friction roll and including shaft means journaled in said supports, said supporting members being formed with slots beneath the bearings of said shafts, shaft means in said slots and carrying between said supporting members a material carrying roll, suspension means for said shaft means, means cooperating with said suspension means for urging said material carrying roll against said friction rolls under gravity action, and a disposed beneath said material carrying roll into which said material carrying roll is adapted to project, said pan being adapted to receive a solution to which a paper making felt is subjected during actual use.

WILLIAM B. PETKEWICZ.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,156,803 Norris Oct. 12, 1915 1,990,771 Boden Feb. 12, 1935 2,482,381 Stevens et al Sept. 20, 1949 

